Goals: The Laboratory/Morphology Core provides high quality and consistent support for all of the SCOR investigators who need common methods for analyzing fluids and tissues. The concept of the Laboratory/Morphology Core represents the most economical and efficient use of space, equipment, and skilled personnel. This core has a strong track record of productive and productive interactions with each of the components of the SCOR Program. Specific Aims. Core C provides laboratory and morphology support for the projects in the SCOR Program. The specific aims are: 1) To provide support for biochemical analyses in the SCOR BAL Program (Project 1). 2) To provide histological and morphological support for the SCOR BAL Program (Project 1) and the basic science projects (Projects 2-5). 3) To support interactions between the SCOR program and other collaborating laboratory groups in the United States and Europe in studying ARDS. 4) To facilitate specific studies related to Project 1 and the BAL program, such as investigating alternative ways to sample airspace fluids in patients with ARDS. Specific Methods. The specific methods available through Core C include cellular analyses, enzyme immunoassays, histology, electron microscopy, immunocytochemistry, in situ hybridization, and assays to detect cellular apoptosis and cell cycling.